Fuel pump modules are used to pump fuel to the fuel injectors of internal combustion engines from the fuel tank. These fuel pump modules typically include various sensors. One such sensor on the fuel pump module is a fuel level sender, often incorporating a float arm for monitoring the level of fuel in the tank connected to a sensor that relays the level of fuel to the fuel gauge on the instrument panel. The fuel level sender is usually located near the bottom of the fuel pump assembly.
Fuel tanks typically have embosses on the floor of the tank and an opening at the top of the tank for receiving, locating, and holding the fuel pump module within the fuel tank. These embosses on the fuel tank can interfere with the fuel level sender by obstructing the movement path of the float arm. One way the embosses can interfere is by preventing the float arm from reaching the lowest point of the float arm movement path, thus causing the fuel gauge to fail to indicate a near-empty or empty condition. Another way the embosses can interfere is by pinching the float arm between the emboss and the fuel pump module, thus causing the fuel gauge to indicate an always empty or otherwise erroneous condition.